I LOVE finding out about different ways to appreciate the Sun and light in general. Use this forum to post your info or questions about various outside the mainstream ways to appreciate our life giving star!

Hi I have been playing with Ardruino boards over the last few months. These are very cheap and very versatile. They literally can control or monitor anything.

One project was a weather station which updates to the internet every 5 mins, measuring pressure, temp and humidity and all can fit into a matchbox!

I have purchased an Ardruino Uno R3 which can be bought for as little as £6.00. this board can measure the frequency of a pwm signal from a sensor ie the FGM 3 with a program literally a few lines long called "freqcount".

Loads of other boards can be added to the R3 like an ESP8266 which is a WiFi Board which again are only a few pounds.

The signal can the be sent to a site called Thingspeak which then puts the data in graph form and can be easily accessible by mobile phone app or any device really.

The plan is to put this together and see how it performs. The main thing I need to test is temperature and timing on the board and it's effects.

If this is a problem I think it can be solved by adding a very accurate real time clock board to it. This RTC board has a built in temperature monitor which compensates for temp effects on the quartz crystal and again is the size of a stamp!

Very early stage of this but if it works it's tiny, excellent price range and data can be seen from anywhere.

Cool. Looking forward to seeing more from this little (and cheap) device.

Temperature fluctuations are the main issue I've found with my magnetometer. I've had to go to significant lengths to protect the integrity of the signal data using close temperature control at both the sensor and the receiver. The other issue is the effect of sporadic 'noise'; odd glitches caused by everyday objects or stray electromagnetic signals which I filter out of the data to eliminate spurious spikes. You'll need to address these in order to clean up the output charts.

Cool. Looking forward to seeing more from this little (and cheap) device.

Temperature fluctuations are the main issue I've found with my magnetometer. I've had to go to significant lengths to protect the integrity of the signal data using close temperature control at both the sensor and the receiver. The other issue is the effect of sporadic 'noise'; odd glitches caused by everyday objects or stray electromagnetic signals which I filter out of the data to eliminate spurious spikes. You'll need to address these in order to clean up the output charts.

Cheers.

Stu.

Yes Stu I use your design but had to disconnect due to room being redecorated etc. So while down I can play with the fgm3 and the boards. As the sensor is still underground and regulated power I can isolate temperature issues at the processor.

First is to regulate power to the board and start getting some data to look at and see what problems there are.

I still have the cooler box and temperature controller setup to use as well.

...this board can measure the frequency of a pwm signal from a sensor ie the FGM 3 with a program literally a few lines long called "freqcount".

So you do not read an analog Signal but a frequency and if I understand it correctly the higher the frequency is, the stronger the magnetic field ?

Thanks and regards Rainer

Hi Rainer the FGM 3 outputs a 5 Volt square wave and the frequency correlates with the magnetic field both higher and lower. They are very sensitive and react to temperature fluctuations and voltage fluctuations as well.

The sensor FGM3 and voltage regulator board are best buried around a meter underground to keep a stable temperature. The reading circuit also needs to be temperature controlled as well wherever it is indoors.

Stu (Carbon60) has a design that works extremely well and has a great writeup on the build using a bat detector to measure the frequency.

I'm trying out this microcontroller which can measure the frequency using a digital input.

...this board can measure the frequency of a pwm signal from a sensor ie the FGM 3 with a program literally a few lines long called "freqcount".

So you do not read an analog Signal but a frequency and if I understand it correctly the higher the frequency is, the stronger the magnetic field ?

Thanks and regards Rainer

Hi Rainer the FGM 3 outputs a 5 Volt square wave and the frequency correlates with the magnetic field both higher and lower. They are very sensitive and react to temperature fluctuations and voltage fluctuations as well.

The sensor FGM3 and voltage regulator board are best buried around a meter underground to keep a stable temperature. The reading circuit also needs to be temperature controlled as well wherever it is indoors.

Stu (Carbon60) has a design that works extremely well and has a great writeup on the build using a bat detector to measure the frequency.

I'm trying out this microcontroller which can measure the frequency using a digital input.

Thank you. I found FGM 3 and will order one. They are in Slovenia. I have som contacts in Germany and so I can let it send to them and from there to Mexico.

FGM 3 costs 32 Euro and shipping to Mexico would cost 55 Euro

One more question. I have a pier which at the base is 1m x 1m and quite high. Could I drill a hole into the pier and bury it there ? The pier year in year out has quite a similar temperature. Look at the pier construction.

Hi all here's the first hit of the CME on the Ardruino board. Findings so far are it dosnt appear to react to the house temperature which is good. It concurs with the magnetometer at Crooktree.

The raised section in the middle is the effect of my own vehicle which can be looked at. Worth noting as well the chart is inverted however the can be easily turned around on the online live chart.
Carl

Are you also able to capture/export the data as a CSV file (frequency and time)?

Stu

Hi Stuart that can be done. This chart is a basic one provided by the Ardruino software instead of pumping out a list of numbers. There are various ways of doing a CSV file live which I will look at this weekend.

Frequency counting is the way to go. When I started my magnetometer project some years back I was looking for a suitable low cost counter, but I couldn't find anything on the market cheap enough with the resolution needed for sub nT measurements. The Arduino ( or Rasperry Pi) micro systems now available seem more than up to the task.

Data logging appears to be pretty straightforward, as does exporting to Excel. Once you get your data into Excel, Carl, it will then be easy to filter out the noise/spikes in your data, even accounting for passing traffic, or parking on your driveway.

Temperature control at the receiver has been the biggest challenge with my design. I'm confident that the Arduino version will eliminate this issue and that a cleaner presentation of your data can be achieved through the use of Excel.